Get Package Costs

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the behavioral disclosure burden. It does this well by revealing the implementation approach ('parsing node_modules paths from the profile') and a meaningful edge case ('Scoped packages (e.g. @babel/core) are handled correctly'). It does not explicitly state that the operation is read-only, but the language 'aggregate' and 'identifies' strongly implies a non-mutating analysis.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences with no filler. The core function is stated first, followed by practical use cases, and a concise note on scoped package handling. Every sentence earns its place and the structure makes the tool easy to scan.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple tool with one required parameter and no output schema, the description covers the essential purpose, use cases, input source, and an edge case. It stops short of describing the exact return format (e.g., sorted list, object keys), which is slightly notable given no output schema exists.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents both parameters (profileId and limit). The description does not add significant parameter-level detail beyond noting that parsing occurs on the profile, which is already implied by the schema description 'Profile ID returned by load_profile'. Baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's function: 'Aggregate CPU self-time by npm package.' This is a specific verb-resource pair that distinguishes it from siblings like get_hotspots (which likely targets functions/lines) and profile summary tools. The mention of 'third-party dependencies' and 'node_modules paths' further clarifies the exact scope.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives explicit use-case context: 'Useful for deciding which packages to replace, lazy-load, or avoid.' This tells an agent when to invoke the tool. However, it does not name specific sibling alternatives or explain when not to use it, so it falls short of full routing guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.